Method generate

dgraph/cmd/migrate/table_guide.go:35–55

As an example, if the employee table has 3 columns (f_name, l_name, and title), where f_name and l_name together form the primary key. Then a row with values John (f_name), Doe (l_name), Software Engineer (title) would generate a blank node label _:person_John_Doe using values from the primary key c

(info *sqlTable, values []interface{})

// would generate a blank node label _:person_John_Doe using values from the primary key columns
// in the alphabetic order, that is f_name, l_name in this case.
func (g *usingColumns) generate(info *sqlTable, values []interface{}) string {
	if g.primaryKeyIndices == nil {
		g.primaryKeyIndices = getColumnIndices(info, func(info *sqlTable, column string) bool {
			return info.columns[column].keyType == primary
		})
	}

	// use the primary key indices to retrieve values in the current row
	var parts []string
	parts = append(parts, info.tableName)
	for _, columnIndex := range g.primaryKeyIndices {
		strVal, err := getValue(info.columns[columnIndex.name].dataType,
			values[columnIndex.index])
		if err != nil {
			logger.Fatalf("Unable to get string value from primary key column %s", columnIndex.name)
		}
		parts = append(parts, strVal)
	}

	return fmt.Sprintf("_:%s", strings.Join(parts, separator))
}

// A usingCounter generates blank node labels using a row counter
type usingCounter struct {